CMB polarization from secondary vector and tensor modes

S. MOLLERACH; D. HARARI; S. MATARRESE

PHYSICAL REVIEW D - PARTICLE AND FILDS

American Physical Society

Año: 2004 vol. 69 p. 1 - 11

0556-2821

We consider a novel contribution to the polarization of the Cosmic Microwave Background induced by vector and tensor modes generated by the non-linear evolution of primordial scalar perturbations. Our calculation is based on relativistic second-order perturbation theory and allows to estimate the effects of these secondary modes on the polarization angular power-spectra. We show that a non-vanishing B-mode polarization unavoidably arises from pure scalar initial perturbations, thus limiting our ability to detect the signature of primordial gravitational waves generated during inflation. This secondary effect dominates over that of primordial tensors for an inflationary tensor-to-scalar ratio $r